Multiple ladder



April 9, 1946. w. SH 7 2,397,972

MULTIPLELADDER Filed Aug. 22, 1944 r INVENTOR M42 T52 Z Mas/me ATTORNEY Patented Apr. 9 1946 UNITED STATES. PATENT ()FFICE 2,397,972 MULTIPLE LADDER Walter I. Mosher, Harpursville, N. Y., assignor to Noel L. Dahlander, New Milford, Pa.

Application August 22, 1944, Serial No. 550,548

4 Claims.

This invention relates to debarkation ladders in general, and more especially to multiple ladders of the type extensively used in emergency debarkations.

Among the objects of the present invention, it is aimed to provide an improved boom for use with multiple ladders of the type extensively used in emergency debarkations suitable for maintaining the multiple ladders spread apart during use and for spacing the ladders from the side of the vessel with which they are being used to facilitate climbing down or up the same.

It is still another object of the present invention to provide an improved boom light in weight and composed of metal capable of withstanding destruction or injury by ordinary fires, explosions and the like.

These and other features, capabilities and advantages of the invention will appear from the subjoined detail description of one specific embodiment thereof illustrated in the accompanying drawing in which Figure 1 is a front elevation of a multiple ladder equipped according to the present invention.

Fig. 2 is an enlarged fragmental front elevation of the ladder.

Fig, 3 is a section on the line 3-3 of Fig. 2.

Fig. 4 is a fragmental plan showing the connection between a rung and a chain.

In the embodiment shown, there is illustrated a multiple chain ladder of the type today extensively used for seagoing vessels. These ladders frequently, as illustrated, have a spreader l and a spreader 2 at the top and bottom of the ladder equipped with eyelets 3 and 4, respectively, to

receive the ends of the flexible suspensory elements 5, in the present instance, chains having links of the Look link type. Excellent results have been achieved when the spreaders are about five feet three inches long and composed of galvanized iron having an outside diameter of about one and one half inch and an inside diameter of about one and one-quarter inch.

To the suspensory elements 5, six being shown in the present instance, and between each two adjacent suspensory elements 5, there are connected, preferably pivotally connected, the ends of the rungs B. The rungs 6 may be composed of wood or the like and as shown have metal ferrules I secured to the ends thereof and U-shaped clips 8, the shanks 9 of which extend to and beyond the ferrules l and are secured in place by machine screws extending through a rung 6 and connected at their ends to the shanks 9, one machine screw [0 preferably extending also tain decided advantages.

through a ferrule I to secure it in place while the other machine screw ll clears such ferrule I, see Fig. 2. The shanks 9 of each clip 8 have an intermediate loop formed, connecting web l2 to receive the shank of a link for pivotal connection.

The rungs 6, in the present instance, of adjacent ladder sections are in alinement with one another, although the connection shown of course also permits of a staggered arrangement.

The distance between successive rungs of any one ladder section may vary, excellent results having been achieved when the uppermost rung 6 is about thirteen inches from the spreader l and the successive rungs of a particular ladder section are spaced about thirteen inches from one of boom now to be described and its relation to a multi-chain ladder such as aforesaid.

Booms have been extensively used with multiple chain ladders not only to aid in maintaining the ladder spread apart ready for use, but also to space the ladder from the side of the vessel with which it is being used. The booms heretofore extensively used have generally been composed of wood. When so composed of wood, it has been difficult to obtain satisfactory results unless the boom had a diameter approximating four inches and was composed of a wood averaging between thirty pounds and thirty-four pounds for a length about five feet three inches, and about four inches in diameter.

As a result of tests, it has been found that the boom here disclosed meets every requirement of the aforesaid boom, but in addition includes cer- As an instance, the present boom made according to the present in vention is much lighter in weight and much easier to handle, a boom made according to the present invention averaging about eighteen pounds per boom as compared to thirty pounds to thirty-four disks l3 composed of galvanized iron of about five and one-quarter inches in diameter by onesixteenth of an inch in thickness and having an outer flange I4 of about three-eighths of an inch in width. These disks each are provided with a plurality of openings, two in the present instance, numbered I and I6, equally spaced from the axis of the disk I3, and an arcuate recess II, the radius of which in the present instance is equal to the radius of each of the openings I15 and IB to accommodate similarly, sized bars or pipes, as an instance, a cylindrical'galvanized iron pipe of about three-quarters of an inch in outside diameter. Excellent results have been achieved when the inner diameter of the pipe is about one-half inch. Pipes of this diameter and character, IS, IS and 20, are provided; and extended through the six disks I3 with the flanges I4 of the three disks I3 on the left extending toward the right, and the flanges I4 of the three disks I3 on the right extending toward the left. The arcuate recess I1 preferably is equidistant from the openings I5 and I6 with a view to uniformly distributing the stress and strain absorbing mediums.

It will also'be noticed that in the interest of 7 effective assembly, the center of the arcuate recess I! is inside of a straight line drawn from one edge 2| to the other edge 22 of the recess II. In other words, the peripheral arc of the recess II exceeds 180, thereby making it necessary to slide the pipe ZIlaxially into place in the recess I1, and yet have a suflicient portion of the pipe 20 exposed or disposed beyond the periphery of the disks '6, see Fig. 3, so that the pipe 20 will rest against the chains 5 whereby the chains 5 will effectively cooperate with the pipe 2 to space the ladder from the side of the vessel With'which the ladder is to be used, while on the other hand, in the interest of reducing wear to a minimum, instead of the pipes I8 and I9 being exposed to engagement with the side of the vessel, the disks I3 here extend beyond the pipes !8 and I9 and only the disks I 3' engage the side of the vessel.

In order to position the pipe 20 with respect to the chains 5, the disks I3 each have a smaller opening 23 to receive the links 24 having one loop 25 entering the opening 23 and the other loop 26 gripping a link 21 of a chain 5. Excellent results have been achieved When this opening approximates seven-sixteenths of an inch and the same is positioned adjacent to the flange I4 and about equidistant from the openings I I and I 8 as shown in Fig. 3.

The disks I3 as shown in Figure l are preferably spaced to aline with the chains 5, so that the links 24 of each disk will be anchored to one of the chains 5. Suitable means may be provided to anchor the disks 6 in place on the pipes I8, I9 and 29, such for instance as welding, see the welding burrs 28 shown in Fig. 2.

It is obvious that various changes and modificationsmay be made to the details of construction without departing from the general spirit of the invention as set forth in the appended claims.

T. claim:

1. In a multiple ladder, the combination of a plurality of suspensory elements, a plurality of sets of rungs, each set connected at its ends to two adjacent suspensory elements, booms or spacers disposed between the ladder and the side of the vessel with which the ladder is being used, each boom including a plurality of equally sized ,metal disks parallel to one another, a plurality of metal tending beyond some of said bars to engage the side of the vessel with which said ladder is to be used and other of said bars extending beyond the peripheral edges of said disk and positioned to engage said suspenso-ry elements, and links pivotally connecting said disks to said suspensory elements.

2. In a multiple ladder, the combination of a plurality of suspensory elements, a plurality of sets of rungs, each set connected at its ends to two adjacent suspensory elements, booms or spacers, each boom including a plurality of metal disks parallel to one another and in alinement with said suspensory elements, three metal pipes extending through said disks, two of said pipes disposed inwardly from the peripheral edges of said disks to enable said disks to engage the side of the vessel with which said ladder is being used and the remaining pipe being disposed to extend beyond the peripheral edges of said. disks into position to engage said suspensory elements, 'and links pivotally connecting said disks to said suspensory elements and spacing said booms from one another in turn to space the ladder from the side of the vessel with which it is being used.

3. In' a multiple ladder, the combination of a plurality of suspensory elements, a plurality of sets of rungs, each set connected at its ends to two adjacent suspensory elements, booms or spacers disposed between the ladder and the side of the vesselwith which the ladder is being used, each boom including a plurality of round metal disks equal in size and parallel to one another three metal bars extending through said disks, two of said bars disposed inwardly from the peripheral edges of said disks to enable said disks to engage the side of the vessel with which said ladder is being used and the remaining bar being disposed to extend beyond the peripheral edges of said disks in position to engage said suspensory elebars extending through said disks, said disks exments, and links pivotally connecting said disks to said suspensory elements and spacing said booms from one another in turn to space the ladder from the side of the vessel with which it is being used.

4. In a multiple ladder, the combination of a plurality of suspensory elements, a plurality of sets of rungs, each set connected at its ends to two adjacent suspensory elements, booms or spacers disposed between the ladder and the side of the vessel with which the ladder is being used, each boom including a plurality of round metal disks equal in size and parallel to one another and in alinement with said suspensory elements, a plurality of metal pipes extending through said disks, the disks extending beyond some of said pipes to enable said disks to engage the side of the vessel with which the ladder is being used and other of said pipes extending beyond the peripheral edges of said disks in position to engage said suspensory elements, and links pivotally, connecting said disks to said suspensory elements spacing said booms from one another in turn to space the ladder from the side of the vessel with which it is being used, there being an even'num-ber of 

